Overview
- Engineers at the University of California, San Diego published a Nature Communications paper describing CHARM, a ring that uses an osmotic hydrogel to draw finger sweat into electrochemical sensors and wirelessly send readings to a companion smartphone app.
- In small trials with participants with and without Type 1 diabetes, the ring’s sweat glucose readings closely matched continuous glucose monitor measurements and its ketone readings aligned with traditional blood meters.
- The current prototype is bulky and clamp‑like, relies on a hydrogel that must be replaced, runs about 12 hours per charge and lacks a convenient recharge method, so it cannot yet provide multi‑day continuous monitoring.
- Researchers say the next steps are large clinical studies across the full glycemic range, improvements to hydrogel longevity and battery design, and consumer‑grade streamlining before regulators or device makers could consider adoption.
- Noninvasive molecular sensing from sweat has long been a goal for wearables, and if CHARM’s approach is validated and miniaturized it could help optimize insulin dosing and broaden the health data rings can provide.